External rotary seal for a swivel joint



un 1, 1 3. w. BRUNDAGE 3.186.137

EXTERNAL ROTARY SEAL FOR A SWIVEL JOINT Filed March 9, 1962 2Sheets-Sheet 1 IE I 5-. 3..

INVENTOR.

BENJAMIN w. BRUNDAGE Wam ATTORNEYS June 1, 1965 5 w, BRUNDAGE 3,186,737

EXTERNAL ROTARY SEAL FOR A SWIVEL JOINT Filed March 9, 1962 2Sheets-Sheet 2 V FIE--5;

L J INVENTOR.

BENJAMIN W. BRUNDAGE v46; ATTORNEYS United States Patent T 3,186,737EXTERNAL ROTARY SEAL FUR A SWIVEL JGINT Benjamin W. Brundage, 227 ElCerrito Ave., Piedmont, Calif. Filed Mar. 9, 1962, Ser. No. 178,613 2Claims. (Cl. 285-45) This invention relates to an improved swivel jointsuch as is employed in providing a drain for a floating roof on a tank.

To reduce fire and explosion hazard and evaporation, and to preventcontamination, it is usual to provide a floating roof on a tank used forthe storage of liquid hydrocarbons such as various petroleum products.The tanks employed are usually of relatively large size, frequentlybeing of the order of several hundred feet in diameter. It will beobvious that in the event of rainfall or melting snow, the removal ofwater from the tank roof can provide a problem, particularly if it iseither desirable or essential that the water not mix with the liquidstored in the tank.

As will be presently related in further detail, the usual means providedfor effecting water removal includes several lengths of pipe extendingdownwardly from a sump in the roof to lead the water off from a sump inthe floating roof to the outside of the tank. The drain pipe must becapable of accommodating itself to the height of the roof above thebottom of the tank. This is usually achieved by joining the several pipelengths together with swivel joints. It will be obvious that if thejoints are not fluid tight, the liquid stored in the tank will find itsway into the drain and, as a consequence, the valuable product of thetank may be lost to a sewer. In some instances, when it becomes apparentthat one or more of the swivel joints are leaking, the drain line may beclosed with a valve. However, if this drain is not opened, in the eventof a rainfall the collected water on the roof may cause the roof tosink.

In accordance with the present invention, I have provided a novel andimproved swivel joint which is effectively sealed against entrance ofthe product in which the swivel joint is immersed.

It is generally a broad object of the present invention to provide anovel and improved seal for a swivel joint.

A further object of the present invention is to provide an improvedswivel joint for use in the drain on a floating roof.

The invention includes other objects and features of advantage, some ofwhich, together with the foregoing, will appear hereinafter when thepresently preferred form of swivel joint of this invention is disclosed.

In the drawing accompanying and forming a part hereof:

FIGURE 1 is a section taken through a tank equipped with a floating roofand showing the typical drain structure provided for removing rain waterfrom the roof.

FIGURE 2 is a side elevation with portions thereof broken away toillustrate the construction of the swivel joint embodying thisinvention.

FIGURE 3 is a section taken along the line 3-3 of FIGURE 2.

FIGURE 4 is an exploded view in perspective showing the assembly of theswivel joint and the seal of FIG- URE 2.

FIGURES 5 and 6 are sections taken through other forms of sealsembodying the present invention.

Referring to FIGURE 1, the tank 6 is provided with a floating roof 7.The construction of the tank and roof are, of course, conventional andWell known, the roof being adapted to float on the surface of the liquidin the tank and slide up and down, sealing contact with the side wallsthereof being maintained by shoes 8. Gen- 3,185,??? Patented June 1,1965 ice erally, such a floating roof will slope inwardly to a centralsump 9 for the collection of water which may result from rain or meltingsnow.

To remove the water from the sump, the drain, generally indicated at 10,is provided. This drain is made up of several lengths of pipe indicatedat 11, 12, 13, 14 and 15. The last length extends to a valve 16 outsideof the tank; the valve 16 is left open to drain 01f water. Each of thepipe sections is joined to the next by a swivel joint, these beingindicated respectively at 17, 18, 19 and 20. A flexible element such aschain 21 may be extended between the roof and the pipe length 14 so thatat least a portion of the weight of the pipes is carried by the roof andthe pipes are not forced to support themselves.

As appears in FIGURE 2, each swivel joint generally includes an Lsection 26 and a straight section 27, the two being mounted one upon theother so that one can rotate with respect to the other. Thus, thecylindrical end 28 of section 27 is received within the tubular portion29 of the L section 26. Two sets of ball bearings 32 mount the end 28for an easy rotational movement in the tubular portion 29. A sealstructure generally indicated 33 is provided between end 34 oncylindrical end 28 and wall 35 on the tubular portion 29 to seal oneside of the bearings. Another seal structure 36 is provided on the otherside of the bearings between end 28 and tubular portion 29.

In the form of the swivel joint shown in FIGURE 2, the L 26 and thestraight section 27 are each provided with flanged ends 37 and 38, andthe structure is shown as generally assembled by welding.

The swivel joint structure can be otherwise provided. For example,instead of the flanged ends 37 and 38, one can provide threaded ends. Ingeneral, the structure so far described is that of a swivel joint whichis currently on the market and which is sold as the Chiksan swiveljoint. One can use any swivel joint, however, and the invention is notlimited in application to the exact struc ture disclosed, for there arenumerous swivel joints available.

In accordance with the present invention, I provide an additional sealfor the annular space between end 41 of the tubular portion 29 and theexterior surface of the end 27. Thus, as appears particularly in.FIGURES 2, 3 and 4, I provide an annular washer 42 of a suitableresilient material fitting snugly along section 27 and over end 41. Asappears in FIGURE 2, washer 4-2 fits over and extends on both sides ofthe annular opening between the end 28 and the receptacle 29.Preferably, the exterior of section 27 and the end 41 are faired intoone another to provide a smooth support for the washer.

To retain the flexible washer 42 in place under adequate sealingpressure, I provide a backup ring 43. To permit this ring to beremovably mounted, it is provided in like halves, each having an innersemi-circular recess 44 to enable a ring half to fit snugly on the beadof weld 46. The outer periphery of each ring half is recessed as at 47to receive a clamping ring 48 which mounts the ring halves in position.

Mounted on one side face of each ring half is a semicircular resilientmember 49 having a curved or chamfered inner face 51. Upon the resilientmembers being compressed, the curved or chamfered face forces theannular washer 42 in snugly against the annular end 41 of the tubularportion 29 and against the side wall of section 27 to effect a seal.Compression of the ring halves 49, upon their assembly, is eifected bythe clamp 52.

In place of utilizing split rings 43 to provide the backup for theresilient members 49, the side wall of the section 27 may be providedwith an annular shoulder 61 which provides a stop or backup as in FIGURE5. Or,

if desired, a ring 62 may be welded in place as in FIG- URE 6.

In use, the only portion of the flexible washer 42 which is subject towear is that which is engaged with the annular end 41 of the tubularportion 29. The ring is held effectively over the annular openingbetween end 41 and the side Wall of section 27, so that the liquid inthe tank 6 cannot pass the ring and so enter the joint to attack thehearing. If the bearings are attacked, the nice fit of the rotatingparts will be lost. Thereafter, upon rotation of the elements of thejoint, the seal 33 will be damaged and so will becomeinelfective; thiswill permit the product to leak through the joint into the open drainline and so be lost.

I claim:

1/ In a swivel joint:

(a) a first cylindrical member having a tubular portion terminating inan end;

(b) a second cylindrical member having an end rotatably mounted withinsaid tubular portion of the first member; 4

(c) bearing means mounting and retaining said end of the said secondmember for rotation in the tubular portion of the first member with theend of the tubular portion of said first member fitting closely adjacentto but spaced from the second member to provide an annular space betweenthe said first and second members;

(d) a shoulder on the said second member immediately adjacent said endof the said first cylindrical member and disposed substantially in thesame radial plane therewith whereby to provide a substantially 4continuous surface including the said end of the said first cylindricalmember and the said shoulder;

(e) a washer lying against said end of the said first cylindrical memberand against the shoulder of the said second member and extending acrossthe annular space therebetween;

(f) a resilient ring fitted about said second member and engaged withthe said washer;

(g) a stop secured to the said second cylindrical member on the side ofsaid resilient ring opposite from said washer and engaged with the saidresilient ring whereby to prevent the resilient ring from sliding awayfrom the said washer; and

(h) a means for compressing said ring to force the ring into engagementwith said washer.

2. The structure of claim 1 wherein said compressing means comprises aclamp about said resilient ring to force the ring into engagement withsaid washer.

References (Zited by the Examiner UNITED STATES PATENTS 1,296,181 3/19Grigg 277-147 1,460,939 7/23 Boyer 277-138 2,009,744 7/35 -Pfelferle 285337 2,036,537 4/36 Otis 285--281 2,494,598 1/50 Waring 285-351 2,789,8474/57 Jackson 285-276 FOREIGN PATENTS 1,065,233 9/59 Germany.

CARL W. TOMLIN, Primary Examiner.

1. IN A SWIVEL JOINT; (A) A FIRST CYLINDRICAL MEMBER HAVING A TUBULARPORTION TERMINATING IN AN END; (B) A SECOND CYLINDRICAL MEMBER HAVING ANEND ROTATABLY MOUNTED WITHIN SAID TUBULAR PORTION OF THE FIRST MEMBER;(C) BEARING MEANS MOUNTING AND RETAINING SAID END OF SAID SECOND MEMBERFOR ROTATION IN THE TUBULAR PORTION OF THE FIRST MEMBER IWTH THE END OFTHE TUBULAR PORTION OF SAID FIRST MEMBER FITTING CLOSELY ADJACENT TO BUTSPACED FROM THE SECOND MEMBER TO PROVIDE AN ANNULAR SPACE BETWEEN THESAID FIRST AND SECOND MEMBERS; (D) A SHOULDER ON THE SAID SECOND MEMBERIMMEDIATELY ADJACENT SAID END OF THE SAID FIRST CYLINDRICAL MEMBER ANDDISPOSED SUBSTANTIALLY IN THE SAME RADIAL PLANE THEREWITH WHEREBY TOPROVIDE A SUBSTANTIALLY CONTINUOUS SURFACE INCLUDING THE SAID END OF THESAID FIRST CYLINDRICAL MEMBER AND THE SIDE SHOULDER; (E) A WASHER LYINGAGAINST SAID END OF THE SAID FIRST CYLINDRICAL MEMBER AND AGAINST THESHOULDER OF THE SAID SECOND MEMBER AND EXTENDING ACROSS THE ANNULARSPACE THEREBETWEEN; (F) A RESILIENT RING FITTED ABOUT SAID SECOND MEMBERAND ENGAGED WITH THE SAID WASHER; (G) A STOP SECURED TO THE SAID SECONDCYLINDRICAL MEMBER ON THE SIDE OF SAID RESILIENT RING OPPOSITE FROM SAIDWASHER AND ENGAGED WITH THE SAID RESILIENT RING WHEREBY TO PREVENT THERESILIENT RING FROM SLIDING AWAY FROM THE SAID WASHER; AND (H) A MEANSFOR COMPRESSING SAID RING TO FORCE THE RING INTO ENGAGEMENT WITH SAIDWASHER.